A new 380 ton tunnel boring machine (TBM) measuring 14 feet 8 inches tall has arrived on a wastewater treatment project in Alexandria, Virginia.
Dubbed “Hazel”, the tunnel boring machine marks a milestone in the RiverRenew program, run by Alexandria Renew Enterprises (AlexRenew), to improve local waterways, according to the group.
The tunnel boring machine was from Schwanau, Germany, according to the authority.
“Today is a monumental day for Alexandria and our waterways,” Karen Pallansch, chief executive of AlexRenew, said in a prepared statement. “This is a huge step forward in our commitment to delivering healthier waterways by 2025.”
Typically, a TBM is named before it is launched in accordance with 14th-century mining traditions, according to AlexRenew. Tunnel boring machines have historically had a female name, as workers underground looked to Saint Barbara for protection. In keeping with this longstanding custom, AlexRenew has nominated the names of six women whose outstanding contributions to Alexandria, the environment, or the fields of engineering and construction have paved the way for countless others.
As voted by Alexandrians via an online poll, the TBM was unveiled at the ceremony as “Hazel”, in recognition of Hazel Johnson, one of America’s leading pioneers in environmental justice who dedicated her life to solve ecological problems.
The TBM’s arrival and dedication is a milestone for RiverRenew, the largest infrastructure project in Alexandria’s history, and a critical part of meeting a state-mandated deadline to address sewer overflows combined by July 1, 2025. Once lowered more than 100 feet underground, Hazel will construct the new two-mile waterfront tunnel with little disruption to service in an estimated journey of just over one year.
When completed, the RiverRenew tunnel system will prevent more than 120 million gallons of combined sewage from polluting the Potomac River, Hunting Creek and Hooffs Run each year, according to AlexRenew.
Brown and Caldwell, a leading environmental engineering and construction services firm, is advising the owner on the RiverRenew program.
“This is truly a generational project – for us as engineers and planners – but also for Alexandria and future generations who will benefit from healthier waterways,” said Justin Carl, Brown and Caldwell’s project manager, in a statement.